The MISTELS program to measure technical skill in laparoscopic surgery : evidence for reliability

Abstract

Background: The McGill Inanimate System for Training and Evaluation of Laparoscopic Skills (MISTELS) is a series of five tasks with an objective scoring system. The purpose of this study was to estimate the interrater and test-retest reliability of the MISTELS metrics and to assess their internal consistency.

Methods: To determine interrater reliability, two trained observers scored 10 subjects, either live or on tape. Test-retest reliability was assessed by having 12 subjects perform two tests, the second immediately following the first. Interrater and test-retest reliability were assessed using intraclass correlation coefficients. Internal consistency between tasks was estimated using Cronbach's alpha.

Results: The interrater and test-retest reliabilities for the total scores were both excellent at 0.998 [95% confidence interval (CI), 0.985-1.00] and 0.892 (95% CI, 0.665-0.968), respectively. Cronbach's alpha for the first assessment of the test-retest was 0.86.

Conclusions: The MISTELS metrics have excellent reliability, which exceeds the threshold level of 0.8 required for high-stakes evaluations. These findings support the use of MISTELS for evaluation in many different settings, including residency training programs.